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New Journal of Chemistry
Page 7 of 9
DOI: 10.1039/C8NJ00316E
Journal Name
ARTICLE
shown in Fig. 8b. When Mo/g-C3N4 was removed from the successively declined during recycling in the non-selective
reaction mixture at 10 min, the reaction (catalysis) practically oxidation of MB, no appreciable loss of activity was observed
stopped. Additionally, no appreciable dye reaction was for the selective oxidation of MPS after a five-cycle test,
observed when the leached solution obtained after isolation of demonstrating the great potential of the developed catalyst
the regenerated catalyst was used for MB degradation, for selective oxidation.
indicating that soluble Mo species were not active for dye
oxidation.
Conflicts of interest
On the other hand, the Mo/g-C3N4 catalyst maintained its high
activity and selectivity for oxidation of methyl phenyl sulfide to
sulfoxide (Fig. 8). During the five-run recycling test, the
conversion remained between 90−94%, with a selecꢀvity
exceeding 99% for all tests.
There are no conflicts to declare.
Acknowledgements
The authors gratefully acknowledge financial support from the
CNPq, FAPEMIG (Universal APQ-02616-15), CEFET-MG,
Microscopy centre of UFMG,…..
Notes and references
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Figure 8. Recycling study for selective oxidation of methyl phenyl sulfide over
Mo/g-C3N4. Conditions: 1 mmol of methyl phenyl sulfide, 25 mg of Mo/g-C3N4, 1
mmol of H2O2, 15 mL of methanol, T = 25 °C, 90 min.
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Mo/g-C3N4 catalyst for MPS oxidation might be ascribed to low
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In summary, highly dispersed Mo species were successfully
prepared on g-C3N4 and the composite was characterized. The
material was applied as a catalyst for oxidation of various
substrates with hydrogen peroxide or TBHP as the oxidant. The
results indicated that the Mo(VI) sites that were stabilized on
the triazine ring of g-C3N4 can interact with H2O2 or TBPH,
forming peroxo-Mo (VI) groups, which are active for oxidation.
Initially, the catalyst was evaluated in the non-selective
oxidation of MB. ESI-MS measurements confirmed that MB
undergoes successive oxidation reactions with probable
mineralization. The catalyst exhibited high efficiency for
selective oxidation of sulfides to sulfoxides and N- compounds
to the corresponding N-oxides under mild conditions, as well
as potential application in the epoxidation of olefins with
TBHP. Despite the fact that the activity of Mo/g-C3N4
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